Grass pollen allergy is one of the most important allergic diseases world-wide. Several meadow grasses, like timothy grass and rye grass, contribute to allergic sensitizations, but also allergens from extensively cultivated cereals, especially rye, make a profound contribution. The group 4 allergens are well known as important major allergens of grasses. We have cloned for the first time group 4 sequences from Phleum pratense, Lolium perenne, Secale cereale, Triticum aestivtum, and Hordeum vulgare, and investigated the IgE-reactivity of recombinant Ph1 p 4 as a candidate for allergy diagnostic and therapeutic applications. (c) 2005 Elsevier Inc. All rights reserved.